Process for formation of contact conductive layer in a semiconductor device

Abstract

A method for forming a contact between a conductive layer and a portion of the substrate during manufacture of a semiconductor device is disclosed. The process includes the steps of: (a) covering a semiconductor substrate with an insulating layer, and forming a contact hole on the portion where a contact is to be formed; (b) forming a metal layer on the whole surface of the substrate, and implanting positive ions into the metal layer; and (c) heat-treating the whole substrate so as to form a silicide layer. The metals used are those which can react with silicon to form a silicide, and may be selected from high melting point metals including Co, Ti, Ta, Ni, Mo, and Hf. The ions used are ions including H+ or halogen element ions, and a heat treatment is carried out so that the implanted positive ions may spread on/in the grain boundaries, or that the positive ions may bond with dangling bonds. Further, a silicidation heat treatment is carried out so that the silicide would be formed on the portion where the metal and the silicon substrate contact together. These heat treatments may be carried out simultaneously. The heat treatment for the spreading of the positive ions is carried out at a low temperature of about 300°-500° C., while the heat treatment of the silicidation reaction is carried out at a proper temperature depending on the metal used.

What is claimed is: 
     
       1. A process for forming a contact between a conductive layer and a semiconductor substrate in a semiconductor device, comprising the steps of: (a) forming an insulating layer on the semiconductor substrate, and removing a portion of the insulating layer for opening a contact hole where the contact is to be formed;   (b) forming a metal layer over the surface of the substrate, and implanting positive ions including hydrogen or halogen ions into the metal layer; and   (c) carrying out a heat treatment of the substrate so as to form a silicide layer.   
     
     
       2. The process of claim 1, wherein, at step (b), the metal of the metal layer comprises a material reactive with silicon to form a silicide. 
     
     
       3. The process of claim 2, wherein the metal comprises a metal selected from among Co, Ti, Ta, W, Ni, Mo, and Hf. 
     
     
       4. The process of claim 1, wherein, at step (c), a heat treatment is carried out so that the implanted positive ions spread on/in grain boundaries of the metal layer, and so that the positive ions bond with dangling bonds, and a silicidation heat treatment is carried out so that the silicide layer forms on the portion of the semiconductor substrate where the metal layer contacts the semiconductor substrate. 
     
     
       5. The process of claim 1, wherein, at step (c), a heat treatment is carried out so that the implanted positive ions spread on/in grain boundaries of the metal layer, and so that the positive ions bond with dangling bonds, and simultaneously a silicidation heat treatment is carried out so that the silicide layer forms on the portion of the semiconductor substrate where the metal layer contacts the semiconductor substrate. 
     
     
       6. The process of claim 4, wherein the heat treatment for the spreading of the positive ions is carried out at a temperature of about 300°-500° C. 
     
     
       7. The process of claim 1, wherein, in accordance with the conduction type of the semiconductor device, the positive ions are selected from among BF 2   + , BF + , BCl +  ions for a P-type semiconductor device, and the positive ions are selected from among PH 2   +  or PH +  ions for an N-type semiconductor device. 
     
     
       8. A process for forming a junction and a contact conductive layer for a semiconductor device, comprising the steps of: forming an insulating layer on a semiconductor substrate, and forming a contact hole in the insulating layer at a portion of the semiconductor substrate where the contact is to be formed;   depositing a metal layer over the surface of the substrate;   implanting positive ions including hydrogen ions into the metal layer;   carrying out a heat treatment on the substrate, wherein the hydrogen ions spread on/in grain boundaries of the metal layer, and the hydrogen ions bond with dangling bonds at grain boundaries of the metal atoms comprising the metal layer; and   carrying out a silicidation heat treatment so as to form a silicide layer on the portion of the substrate where the metal layer contacts the substrate.   
     
     
       9. The process of claim 8, wherein the heat treatment and the silicidation heat treatment are simultaneously carried out in a single step. 
     
     
       10. The process of claim 8, wherein the heat treatment is carried out at a temperature of about 300°-500° C. 
     
     
       11. A process for forming a junction and a contact conductive layer of a semiconductor device, comprising the steps of: forming an insulating layer on a semiconductor substrate, and forming a contact hole in the insulating layer;   depositing a metal conductive layer on the overall surface;   implanting hydrogen-containing ions or halogen-containing ions into the metal conductive layer;   carrying out a heat treatment for diffusing ions into the substrate so as to form an impurity junction, and for diffusing hydrogen or halogen ions on/in grain boundaries of the metal conductive layer.   
     
     
       12. The process of claim 11, wherein the implanted ions comprise PH 2  ions or PH ions, and the heat treatment step comprises the sub-steps of: decomposing the PH 2  ions or PH ions into phosphorus ions and hydrogen ions, wherein the hydrogen ions diffuse on/in the grain boundaries of the metal conductive layer or bond with dangling bonds at grain boundaries of the metal conductive layer; and   causing the phosphorous ions to diffuse into the substrate to form an N-type impurity junction, and forming a silicide where the metal conductive layer contacts the substrate.   
     
     
       13. The process of claim 11, wherein the implanted ions comprise BF 2 , BF, or BCl ions, and the heat treatment step comprises the sub-steps of: decomposing the BF 2 , BF, or BCl ions into boron ions and fluorine or chlorine ions, wherein the fluorine or chlorine ions diffuse on/in the grain boundaries of the metal conductive layer or bond with dangling bonds at grain boundaries of the metal conductive layer; and   causing the boron ions to diffuse into the substrate to form a P-type impurity junction, and forming a silicide where the metal conductive layer contacts the substrate.